Extreme allergy. Home remedies either.

Hello doctor I have been facing the problem since last 2 months. When I am exposed to allergens, I continuously sneeze and mucus runs out of my nose Whenever I have the allergy attack it lasts very long even 6-7 hours continuously. I usually avoid allergens but if by chance I am exposed to them, I cannot control sneezing and runny nose I visited to doctor also(twice, first to an MD and then to an ENT SPECIALIST) The first time the doctor prescribed cetirizine which didn't relive my symptoms Then the ENT SPECIALIST prescribed me levocetirizine which also did not work for me I am in an extreme trouble, I am not able to study due to this problem and my exams are also very near Please prescribe me something which could really help me out Or help me with some home remedies either.